Example 2

What is the mass of 20 gallons of gasoline?

Tomtit [17]

Your answer would be 14.978

3 0

4 years ago

A scale model of a tower is 24 inches tall and 18 inches wide. If the height of the actual tower is 60 feet, what is its width?

alex41 [277]

Answer:

45 feet

Step-by-step explanation:

To find the width of the model, we need to find the scale of the model to the actual tower.

Since we know the height of both towers, we can use that as the basis.

24 inches : 60 feet

12 inches : 30 feet

6 inches : 15 feet

So the width of the tower is 18 inches wide.

18 inches will then be equal to 12 + 7 inches : 30 + 15 feet

18 inches : 45 feet

6 0

4 years ago

Write the equation of the line that passes through (-6,0) and is parallel to the line y=5x-43

AVprozaik [17]

The equation of the line that passes through (-6,0) and is parallel to the line y = 5x - 43 in slope intercept is y = 5x + 30

Solution:

Given that line that passes through (-6, 0) and is parallel to the line y = 5x - 43

We have to find the equation of line

Let us first find slope of line having equation y = 5x - 43

The slope intercept form of line is given as:

y = mx + c ------- eqn 1

Where "m" is the slope of line and "c" is the y - intercept

On comparing equation of line y = 5x - 43 with slope intercept form y = mx + c,

we get m = 5

Thus slope of given line is 5

We know that slopes of parallel lines are equal

Thus the slope of line parallel to given line is also 5

Now let us find equation of line having slope "5" and passes through (-6, 0)

Substitute m = 5 and (x, y) = (-6, 0) in eqn 1

y = mx + c

0 = 5(-6) + c

Thus the required equation is:

Substitute c = 30 and m = 5 in eqn 1

y = 5x + 30

Thus the required equation of line is found

8 0

3 years ago

The quality control manager of a chemical company randomly sampled twenty 100-pound bags of fertilizer to estimate the variance

lisabon 2012 [21]

Answer:

The 95% confidence interval for the variance in the pounds of impurities would be $3.829 \leq \sigma^2 \leq 14.121$ .

Step-by-step explanation:

1) Data given and notation

$s^2 =6.62$ represent the sample variance

s=2.573 represent the sample standard deviation

$\bar x$ represent the sample mean

n=20 the sample size

Confidence=95% or 0.95

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population mean or variance lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

The Chi square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case the sample variance is given and for the sample deviation is just the square root of the sample variance.

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=20-1=19$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical values.